Create in me a pure heart, O God, and renew a steadfast spirit within me.
We were given a broken heart from birth. Our sinful nature always tainted it. But the Lord purifies it and creates for us a pure heart. Seems pretty straightforward. But even though the work is done from Christ’s perspective, we still have work to do. We have to sanctify ourselves by becoming more like Christ.
For that we need a “steadfast spirit” that seeks to maintain purity and seek out holiness. Nobody is perfect, which is why we ask to the Lord to “renew” that spirit in us. Sometimes when you feel distant from God or just in a dry place in your Faith, it helps to say that to God and ask for him to renew your spirit.